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Gas Insulated Substations (GIS) for Enhanced Resiliency

By George Becker, P.E.

Abstract:

Resiliency is defined as “a means to withstand and to rapidly recover from disruption.” The “Grid of the Future” must be resilient. Electrical substations must also be resilient and operate safely and reliably irrespective of the environments in which they reside. Grid strengthening efforts should improve substation reliability, inherently enhance emergency response and improve recovery strategies related to naturally or human-caused physical events that damage electric substations.

Natural events such as severe weather, are the primary cause of unplanned power outages in the United States. There are a range of natural events that can cause high impact consequential damage to an electric substation, and include storms, naturally occurring environmental conditions, earthquakes, floods, wildlife etc. The severity and impact of recent weather events such as superstorms, large scale tornado outbreaks, coastal flooding and inland river flooding and severe thunderstorms accompanied by strong straight line winds have prompted substation owners to examine design strategies to limit potential damage to substations due to natural events.

Human-caused physical attacks and criminal activity directed at electric substations can be high impact events that cause consequential damage and have long lasting effects. As a result of recent criminal attacks on critical substations, many utilities are examining design strategies to mitigate the effects of criminal activity directed at substations in conjunction with limiting potential damage to substations due to natural events.

Historically, substation designs for the most part have been based on standardized engineering practices and traditional air insulated technology. Given the challenges associated with the threats posed by high impact naturally and human-caused physical events that can damage substations, many utilities are turning to gas insulated technologies as a more resilient solution to harden their substation infrastructure.

This paper discusses benefits considering the use of gas insulated switchgear in the design and construction of electrical substations to harden against infrastructure damage due to natural and human-caused physical threats to substations.

This paper was originally presented at CIGRE Grid of the Future Symposium 2018